Use of a solid dispersion in a pharmaceutical is a technique effective for improving the solubility and absorption properties of an active pharmaceutical ingredient (hereinafter sometimes referred to as “API”), and for enhancing bioavailability of the active pharmaceutical ingredient.
Reports have been already made on solid dispersions, and Patent Literature 1, for example, discloses a solid dispersion that is a pharmaceutical composition containing a poorly water-soluble or water-insoluble HER2 inhibitory substance, and having improved water solubility of the HER2 inhibitory substance.
Patent Literature 2 discloses a pharmaceutical composition containing a poorly water-soluble or water-insoluble lipid rich plaque retracting substance, and having improved water solubility of the lipid rich plaque retracting substance, and Patent Literature 3 discloses a method of producing a solid dispersion wherein a solid substance and a solvent in an amount sufficient to reduce the melting point of the solid substance are hot-melted. Moreover, Patent Literature 4 discloses a solid dispersion containing a p 38 MAP kinase inhibitor.
Furthermore, Patent Literature 5 discloses a solid dispersion comprising a thiazolidine derivative having a specific chemical structure or a salt thereof, a water-soluble polymer (excluding, however, hydroxypropylmethylcellulose and methyl cellulose), and hydroxypropylmethylcellulose and/or methyl cellulose, wherein these ingredients are contained at specific weight ratios.
Patent Literature 6 discloses a solid dispersion preparation containing cilnidipine or a pharmacologically acceptable salt thereof, and at least one water-soluble polymer selected from the group consisting of methyl cellulose, hydroxypropylmethylcellulose, and the like.
Patent Literature 7 discloses a solid dispersion useful as an agent for treating a disease in which dopamine D4 receptor is involved, the solid dispersion comprising a 2-carbonylthiazole derivative, at least one water-soluble polymer selected from hydroxypropylmethylcellulose, hydroxypropylcellulose, polyvinylpyrrolidone, and methylcellulose, and an acid that is an inorganic acid or an organic acid.